Yacy bases its search engine on the principle of a peer-to-peer network.

Instead of using its own servers to index the web, it relies on its users' computers to do the work via software it provides. The information gathered is then shared to a common database, fragments of which are distributed across the network.

Because the answer to any query is obtained from other volunteers' computers rather than a central portal, Yacy says it is impossible for anyone to censor its results.